In the manufacture of goods and articles in the paper, film and foil industries, it is conventional to first form at the mill a wide web of the material, which can later be cut by the converter into smaller, individual rolls or packets. The web, typically provided as a roll, is passed continuously over the knife edge of a plurality of spaced apart slitters for slitting the web into a plurality of individual rolls, which are then wound on separate take-up rollers for packaging and shipping. In conventional practice, a bottom slitter or anvil is used in conjunction with a circular slitter having a sharp cutting edge and is typically known as a top slitter. In a conventional manufacturing process, the bottom slitter is a cylinder having a marginal wall section which is tapered inwardly at an angle of about three degrees to provide a knife edge, and the cutting edge of the top slitter contacts the knife edge of the bottom slitter. When the bottom slitter is rotated by a shaft and motor means, the top knife is rotated in the opposite direction. The web is passed between the slitters and cut by the slitter.
A bottom slitter is manufactured either as a single unitary piece, or as two halves or semicircular members which is known in the industry as a split slitter or band. In the case of a split slitter, each half is placed on a drive shaft, the mating surfaces aligned, and the two members are then rigidly connected. However, for known slitters of this type the mating surfaces align the two parts in an axial direction only. Alignment for the second or radial direction is accomplished when the two halves are mounted on the shaft, which frequently does not give a true alignment because of the clearance between the mounting surface (inside cylindric surface of the slitter) and the mounting member. If the two halves are locked together in a misalgined state, any such misalignment can disturb the direction of cut and/or can result in frayed edges. The two halves must fit and be aligned in both a radial direction and in an axial direction. In order to better assure a proper alignment, and an alignment that can be maintained for some reasonable period of time, the mating surfaces typically have a tongue and groove arrangement or male and female keyways. Although this surface geometry has helped in maintaining alignment, subtle variations still occur which degrade the overall quality of the end product. This same problem exist for similar devices such as anvils and spacers.
A number of tongue and groove locking means or mechanisms have been proposed for joining and aligning two semicircular members. In this regard, attention is directed to the following U.S. Pat. Nos. 732,111; 744,917; 2,488,309; 3,659,490; 3,751,080; 3,889,553; 4,422,348; 4,637,807; and Re. 32,693; and British patent 2213 (01/30/03). However, no locking mechanism is disclosed by the prior art for the interegagement of two semicircular halves showing a means for alignment in both an axial and radial direction.
This invention has therefore as its purpose to provide a locking mechanism such as for a bottom slitter, anvil, band, spacer and the like with improved means for aligning and maintaining engagement of the two halves.